Dermacryl® 79

• Recreational sun protection products
• Daily wear moisturizers with SPF
• Tinted sun protection products
• Color cosmetics
• Face, body, hand, and foot creams and lotions

Solubility:

• As supplied, Dermacryl® 79 film-forming polymer is soluble in ethanol, isopropanol and fatty alcohols, but is insoluble in water.
• The polymer becomes water soluble/dispersible by neutralizing the carboxyl groups with a suitable water soluble base, such as triethanolamine, 2-amino-2-methyl-1-propanol (AMP), ammonium hydroxide, or potassium hydroxide.
• For effective solubilization/dispersion, 100% neutralization of the carboxyl groups is generally recommended.
• Likewise, Dermacryl 79 polymer can be solubilized into an oil system by fully neutralizing the polymer with a long chain amine, such as dimethyl stearamine.

Neutralization:

• Dermacryl® 79 film-forming polymer can be formulated into the water phase or the oil phase of emulsions.
• It can also be formulated into alcohol or hydro-alcoholic systems.

Water phase incorporation:

• Dermacryl® 79 film-forming polymer is typically incorporated into the water phase with neutralization.
• Neutralization levels of 80-100% are recommended.
• The neutralizing agent (i.e., TEA) may be added to the water phase and heated to 80°C before adding the polymer.
• The Dermacryl® 79 polymer may then be slowly sifted in with good agitation and mixed for 20 minutes.
• To simplify addition of Dermacryl® 79 polymer into the water phase, pre-slurry together the neutralizing agent, glycol or glycerin, and Dermacryl® 79 polymer.
• The recommended slurry ratio is 2 parts Dermacryl 79 polymer to 5 parts polyol.
• Add enough alkali to the slurry to neutralize the Dermacryl® 79 polymer and any other ingredients that require neutralization (i.e. Carbomer).
• This pre-slurry should then be immediately added to the water phase of the emulsion.
• The polymer dispersion in the water phase will appear slightly opaque.

Oil phase incorporation:

• Water resistance may also be attained by incorporating Dermacryl® 79 film-forming polymer into the oil phase.
• Long chain amines, added at 80-100% neutralization levels, are the neutralizing agents of choice.
• Prior to adding the polymer, all oil phase ingredients (including neutralizing agent) should be combined and heated to 80°C.
• Dermacryl® 79 polymer should then be slowly sifted in using good agitation and mixed for one half hour.
• If using fatty alcohols that are solid at room temperature, it will be necessary to heat these fatty alcohols above their melting temperature, begin mixing, and then add the Dermacryl® 79 polymer with mixing.

Incorporation into alcoholic systems:

• Dermacryl® 79 film-forming polymer is soluble in and can be easily incorporated into alcoholic systems.
• In the mixing vessel, begin stirring the alcohol.
• Slowly sift in the Dermacryl® 79 polymer.
• If neutralization is required, neutralize with base after the polymer is in solution.

Incorporation into hydro-alcoholic systems:

• Dermacryl® 79 film-forming polymer can be easily incorporated into hydro-alcoholic systems.
• First, add the alcohol to the mixing vessel and begin stirring.
• Add the Dermacryl® 79 polymer to the alcohol, in a polymer to alcohol ratio of no greater than 1:4.
• Once the Dermacryl® 79 polymer is in solution, neutralize with a base.
• For a clear system, Dermacryl® 79 polymer should be neutralized at least 90%.
• Finally, add the water, UV filters and other formulation ingredients.
• In all cases, grittiness is an indication of poor dispersion caused by either under neutralization or improper incorporation.
• Grittiness can be eliminated by adjusting the neutralization level, the temperature or the mixing time used.

SPF retention from an alcohol-based system

• Dermacryl® 79 film-forming polymer is soluble in ethanol without neutralization making it the ideal choice for alcohol-based sunscreen sprays.
• The following table shows a target SPF 30 and SPF 50 formulation and the in-vivo SPF measurements for static and 80 minute very-water resistance.

Contact angle:

• Dermacryl® 79 film-forming polymer maintains integrity after water exposure, allowing for the formulation of durable and long-lasting products.

Shine – gloss meter:

• Evaluation of gloss was performed with the films cast from model systems containing Dermacryl® 79 film-forming polymer on black and white opacity charts.
• Gloss was measured on the scale of 0-90 degrees at a 60° angle. 0-20 degrees is considered a matte finish, 21-69 degrees is considered a semi-gloss finish, and 70-90 degrees is considered a high gloss finish.
• Gloss meter evaluations on model SPF systems containing Dermacryl® 79 polymer showed a lower shine performance, 28.1 degrees on a white background and 30.9 degrees on a black background.
• Dermacryl® 79 polymer provides a low shine film when applied in ethanol-based sunscreen systems.

SPF retention from an emulsion:

• Dermacryl® 79 film-forming polymer can be made soluble in water by neutralizing with a water soluble base, making it an option for formulating water resistant emulsions.
• The following table shows two formulations, one with Dermacryl 79 polymer and one without, and their in-vivo SPF measurements before and after 80 minute immersion in water.
• The use of Dermacryl® 79 polymer in this formulation increases the static SPF and maintains the actives on the skin after an 80 minute immersion in water.

• Dermacryl® 79 film-forming polymer is compatible with a broad range of ingredients commonly used in cosmetic formulations.
• Because Dermacryl® 79 polymer is anionic, compatibility must be evaluated when formulating with cationic raw materials.
• The polymer’s solubility may decrease in the presence of high concentrations of non-polar products, such as paraffin waxes.

• Dermacryl® 79 film-forming polymer is supplied as a white, free-flowing powder.
• Some settling will occur in the drum during shipping.
• Dermacryl® 79 polymer can be stored at ambient conditions.
• When not in use, the drums should be kept covered to prevent contamination and moisture absorption from the atmosphere.